Breathing dust or water droplets containing contaminated bird droppings can lead to several diseases, including a pulmonary disease called Cryptococcosis.

Birds Affect HVAC Systems and Human Health

Birds affect HVAC systems and equipment in many ways. Some ways are obvious. Others? Not so much. Let’s take a look at how birds affect HVAC systems from a mechanical and building health standpoint.

HVAC units located on a roof (RTUs) are most likely affected by birds. Much like other rooftop equipment they weather the elements year round. RTUs are the perfect place for birds to roost and even nest. A frequent population of birds wreaks havoc on RTUs and leads to health issues for occupants.

Birds Affect HVAC Equipment

There are a variety of birds that cause HVAC problems. Some birds like geese are migratory. Other birds like house sparrows, pigeons and starlings make rooftops their homes everywhere. Of these, Pigeons are the biggest problem. This is because of their large, social populations. Aside from being a general nuisance, birds affect HVAC equipment in specific ways.

Filters & Coils

Birds Affect HVAC CoilsBird debris and fecal matter degrades air circulation provided by an RTU. If left unchecked, particulate matter enters the system and builds up on components. The first line of defense are the filters. Bird particulates become trapped and will choke a filter bank. This creates a significant resistance to airflow. So, static pressure increases and compromises RTU efficiency. Bird contaminants also find gaps in the filter housing to enter the coils and drain pan.

Bird debris and droppings clog evaporator coils. Again, this affects static pressure and performance. Fouled coils also degrade airflow, Delta-T and cooling capacity. It’s a recipe for indoor air quality issues and mechanical failure.


Birds affect HVAC systems by pecking off insulation both outside and inside the RTU. Insulation damage to chilled water pipes decrease energy efficiency. However, birds also damage the fiberglass insulation within the RTU. This affects both efficiency and building occupants by releasing fiberglass into the airstream.

Cabinet & Components

Bird droppings are highly acidic. Fecal matter from birds corrodes the metal components of the RTU. Corrosion compromises the structural integrity of HVAC equipment. This leads to holes in the cabinet. In addition, holes in the RTU exterior cause pressurization issues. Not to mention further oxidation of interior components.

Fire Hazards

Birds Affect HVAC Fire SafetyBird nesting materials are flammable. The HVAC system is electrically powered. A short circuit near a nest will spark a fire. A fire will damage the unit and send smoke into the building through the. It can even spread to other area of the building affecting property and life.

Keeping Birds Away

There are a few professional methods to keep birds away. It all starts with routine inspection and maintenance. Any signs of bird infestation need immediate action! Proactive solutions include secure screens around fresh air intakes and bird deterrents. For example, deterrents include bird spikes, predator decoys, reflective tape or bird gel.

Cleaning It Up

Of course, they are many ways to clean up the mess. Our Building Remediation Sciences division provides engineered solutions for optimal HVAC performance. PURE-Steam is an eco-friendly method that disinfects and unclogs coils. HVAC New Life is a total hygienic restoration of an RTU. Our PURE-Duct cleaning utilizes containment and HEPA filtration to deliver IAQ focused results. PURE-Decon is a building disinfection system used to eliminate the toughest microbes.

Birds Affect Building & Human Health

HVAC and building hygiene is also jeopardized by bird infestation. Bird feces and debris pose serious health threats to building occupants. Such detritus is a rich environment for microbial growth. Bacteria and fungi thrive in these conditions. They are easily distributed through a building by the HVAC system. So, breathing dust or water droplets containing contaminated bird droppings can lead to several diseases, including a pulmonary disease called Cryptococcosis.

People become affected in different ways when exposed. This often depends on the type and amount of organism, as well as the individual’s sensitivity. Critical illnesses related to birds cause severe respiratory, digestive and skin symptoms. Some of which are fatal if not immediately treated. More detailed info is in our article The Human Health Dangers of Bird Droppings Associated with Building HVAC Systems.

Identifying Bird Related IAQ Issues

It’s important to identify bird contaminants. Especially if there is an infestation or occupant health complaints. IAQ testing, lab analysis, and reporting is the best way to ensure the health of a building. Our Building Sciences and EDLab divisions help to find the severity of any problems. Building Health Check is a comprehensive program to test indoor environmental conditions. While the HVAC Hygiene Assessment investigates the cleanliness of the system. These tests and their conclusions contribute to the health and safety of a remedial plan.

Birds affect HVAC systems like other pests create issues in other areas of a building. If ignored they will cause damage to equipment and make people sick. Being proactive with HVAC inspection and preventative maintenance is key to keeping birds at bay. Should a problem develop, immediate action is necessary for a safe outcome.

For more info or to get started with testing and clean up please call 1-800-422-7873 or contact us via our website.